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Study: Adolescent marijuana use leaves lasting mental deficits
Medical Xpress ^ | 8-27-2012 | Medical Xpress

Posted on 08/28/2012 8:38:47 AM PDT by fishtank

Study: Adolescent marijuana use leaves lasting mental deficits August 27, 2012 in Psychology & Psychiatry The persistent, dependent use of marijuana before age 18 has been shown to cause lasting harm to a person's intelligence, attention and memory, according to an international research team. Among a long-range study cohort of more than 1,000 New Zealanders, individuals who started using cannabis in adolescence and used it for years afterward showed an average decline in IQ of 8 points when their age 13 and age 38 IQ tests were compared. Quitting pot did not appear to reverse the loss either, said lead researcher Madeline Meier, a post-doctoral researcher at Duke University.

The results appear online Aug. 27 in PNAS. The key variable in this is the age of onset for marijuana use and the brain's development, Meier said. Study subjects who didn't take up pot until they were adults with fully-formed brains did not show similar mental declines. Before age 18, however, the brain is still being organized and remodeled to become more efficient, she said, and may be more vulnerable to damage from drugs.

"Marijuana is not harmless, particularly for adolescents," said Meier, who produced this finding from the long term Dunedin Multidisciplinary Health and Development Study. The study has followed a group of 1,037 children born in 1972-73 in Dunedin, New Zealand from birth to age 38 and is led by Terrie Moffitt and Avshalom Caspi, psychologists who hold dual appointments at Duke and the Institute of Psychiatry at King's College London.

About 5 percent of the study group were considered marijuana-dependent, or were using more than once a week before age 18. A dependent user is one who keeps using despite significant health, social or family problems. At age 38, all of the study participants were given a battery of psychological tests to assess memory, processing speed, reasoning and visual processing.

The people who used pot persistently as teens scored significantly worse on most of the tests. Friends and relatives routinely interviewed as part of the study were more likely to report that the persistent cannabis users had attention and memory problems such as losing focus and forgetting to do tasks.

The decline in IQ among persistent cannabis users could not be explained by alcohol or other drug use or by having less education, Moffitt said. While 8 IQ points may not sound like a lot on a scale where 100 is the mean, a loss from an IQ of 100 to 92 represents a drop from being in the 50th percentile to being in the 29th, Meier said. Higher IQ correlates with higher education and income, better health and a longer life, she said. "Somebody who loses 8 IQ points as an adolescent may be disadvantaged compared to their same-age peers for years to come," Meier said. Laurence Steinberg, a Temple University psychologist who was not involved in the research, said this study is among the first to distinguish between cognitive problems the person might have had before taking up marijuana, and those that were apparently caused by the drug.

This is consistent with what has been found in animal studies, Steinberg added, but it has been difficult to measure in humans. Animal studies involving nicotine, alcohol and cocaine have shown that chronic exposures before the brain is fully developed can lead to more dependence and long-term changes in the brain. "This study points to adolescence as a time of heightened vulnerability," Steinberg said. "The findings are pretty clear that it is not simply chronic use that causes deficits, but chronic use with adolescent onset."

What isn't possible to know from this study is what a safer age for persistent use might be, or what dosage level causes the damage, Meier said. After many years of decline among US teens, daily marijuana use has been seen to increase slightly in the last few years, she added. Last year, for the first time, US teens were more likely to be smoking pot than tobacco. "The simple message is that substance use is not healthy for kids," Avshalom Caspi said via email from London. "That's true for tobacco, alcohol, and apparently for cannabis."

More information: "Persistent Cannabis Users Show Neuropsychological Decline From Childhood to Midlife," Madeline H. Meier, Avshalom Caspi, et al. Proceedings of the National Academy of Sciences, Online Early Edition, Monday, Aug. 27, 2012.

Read more at: http://medicalxpress.com/news/2012-08-adolescent-pot-mental-deficits.html#jCp


TOPICS: News/Current Events
KEYWORDS: cannabis; drugs; drugwar; inhale; marijuana; pot; warondrugs; wod; wodlist; wosd
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RDDB

1 posted on 08/28/2012 8:38:56 AM PDT by fishtank
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To: fishtank

Well, well. That explains a lot, and as a high school teacher, I think this is just a confirmation of my own suspicions.


2 posted on 08/28/2012 8:41:41 AM PDT by struggle (http://killthegovernment.wordpress.com/)
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To: fishtank

3 posted on 08/28/2012 8:43:30 AM PDT by Kenton
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To: fishtank

Looks like there are some things kids can’t handle that adults can. Go figure. I’m just glad the weed dealers card their customers.


4 posted on 08/28/2012 8:47:58 AM PDT by Wolfie
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To: struggle

...aaaaand they then vote democRAT

no cure


5 posted on 08/28/2012 8:49:01 AM PDT by Leo Carpathian (fffffFRrrreeeepppeeee-ssed!)
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To: Leo Carpathian

Choom gang study shows reason for Obama mental deficit...


6 posted on 08/28/2012 8:52:21 AM PDT by tet68 ( " We would not die in that man's company, that fears his fellowship to die with us...." Henry V.)
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To: struggle

I completely disagree................uh, ........ummmm....what were we talking about?.................


7 posted on 08/28/2012 8:52:39 AM PDT by Red Badger (Anyone who thinks wisdom comes with age is either too young or too stupid to know the difference....)
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To: fishtank

"Wait...uhhhhh.....whut?"

8 posted on 08/28/2012 8:55:40 AM PDT by dfwgator
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To: fishtank
Hmm. The kids I knew who smoked dope were not exactly prime specimens to begin with.

9 posted on 08/28/2012 8:55:54 AM PDT by BitWielder1 (Corporate Profits are better than Government Waste)
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To: fishtank


10 posted on 08/28/2012 8:58:03 AM PDT by Iron Munro ("In any compromise between good and evil, it is only evil that can profit." - Ayn Rand)
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To: fishtank
Since teens report that they can get pot more easily than beer or cigarettes, it looks like the most effective way to keep pot out of teens' hands (and still-developing brains) is to legalize it for adults - so sellers have an incentive not to sell to kids (namely, the loss of their legal adult sales).
11 posted on 08/28/2012 9:04:30 AM PDT by JustSayNoToNannies (A free society's default policy: it's none of government's business.)
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To: Red Badger

>>I completely disagree................uh, ........ummmm....what were we talking about?.................

I’d’no man, but I got sum awesome Doritos and like we can watch Cartoon Network until my mom comes home.


12 posted on 08/28/2012 9:26:33 AM PDT by struggle (http://killthegovernment.wordpress.com/)
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To: tet68

Smokin' On The Choom Gang

(To the melody of Sam Cooke's "Workin' On The Chain Gang")

I hear someone singin'
(Hook-Ah! - Hook-Ah!)
(Hook-Ah! - Hook-Ah!)

Well, don't you know
That's the sound of the boys smoking on the Choom Ga-a-ang
That's the sound of the boys smoking on the Choom Gang

All day long they're singin'
(Hook-Ah! - Hook-Ah!)
(Hook-Ah! - Hook-Ah!)

Well, don't you know
That's the sound of the boys smoking on the Choom Ga-a-ang
That's the sound of the boys smoking on the Choom Gang

All day long they deal so hard
Till the sun is goin' down
Dealin' in the schoolyards and hallways
And always, they be feelin' down
You can see them smokin' their lives away
Then you hear somebody sa-ay

That's the sound of the boys smoking on the Choom Ga-a-ang
That's the sound of the boys smoking on the Choom Gang

Can't ya hear them singin'
Mm, I'm goin' home - one of these days
I'm goin' home to find my mama
Whom I love so dear
But meanwhile I be choomin' right he-ere

Well, don't you know
That's the sound of the boys smoking on the Choom Ga-a-ang
That's the sound of the boys smoking on the Choom Gang

All day long they're singin', mm
My, my, my, my, my, my, my, my schoolwork is so hard
Give me donuts - I need sugar
Rollin' "J's" is just so hard


13 posted on 08/28/2012 9:40:26 AM PDT by Iron Munro ("In any compromise between good and evil, it is only evil that can profit." - Ayn Rand)
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To: fishtank

And look at a huge number of his supporters who are also people who burned out their brains in their formative years. The effects are obvious when you see a 20 something Obama Zombie.


14 posted on 08/28/2012 10:11:20 AM PDT by elhombrelibre ("I'd rather be ruled by the Tea Party than the Democratic Party." Norman Podhoretz)
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Since teens report that they can get pot more easily than beer or cigarettes, it looks like the most effective way to keep pot out of teens' hands (and still-developing brains) is to legalize it for adults - so sellers have an incentive not to sell to kids (namely, the loss of their legal adult sales).

Reduce creation of future Democrats - legalize pot for adults!

15 posted on 08/28/2012 10:17:05 AM PDT by JustSayNoToNannies (A free society's default policy: it's none of government's business.)
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To: JustSayNoToNannies

The fact that the weed plant is a bullet proof weed that anyone can grow, means that when it becomes legal, it will not be taxed and everyone with an apartment, or home, or bare spot in the woods, that wants to grow the best pot among their peers, will be doing so and openly sharing it with each other.


16 posted on 08/28/2012 1:01:06 PM PDT by ansel12 (Massachusetts Governors, where the GOP goes for it's "conservative" Presidential candidates.)
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To: fishtank

They become Ron Paul supporters constantly talking about a war on drugs as they munch away I suppose.


17 posted on 08/28/2012 1:02:55 PM PDT by A CA Guy ( God Bless America, God bless and keep safe our fighting men and women.)
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To: ansel12
Since teens report that they can get pot more easily than beer or cigarettes, it looks like the most effective way to keep pot out of teens' hands (and still-developing brains) is to legalize it for adults - so sellers have an incentive not to sell to kids (namely, the loss of their legal adult sales).

The fact that the weed plant is a bullet proof weed that anyone can grow, means that when it becomes legal, it will not be taxed and everyone with an apartment, or home,

Adolescents will be growing pot in their homes?

or bare spot in the woods, that wants to grow the best pot among their peers,

Growing the best pot is not simple; see http://en.wikipedia.org/wiki/Cannabis_cultivation for what's involved.

will be doing so and openly sharing it with each other.

Nobody who dislikes jail will be sharing with minors.

18 posted on 08/28/2012 1:27:15 PM PDT by JustSayNoToNannies (A free society's default policy: it's none of government's business.)
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To: JustSayNoToNannies
Growing great pot is as easy as pie, easier than growing great tomatoes, that is why it is often grown in closets and spare bedrooms, and America is full of people in apartments and homes,and bare patches of ground, and teens know them.

Free pot can be grown in the backyard, but one can use something as simple as this for year round production of enough to keep him and his buddies going with plenty left over.

Image and video hosting by TinyPic

19 posted on 08/28/2012 2:15:03 PM PDT by ansel12 (Massachusetts Governors, where the GOP goes for it's "conservative" Presidential candidates.)
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To: JustSayNoToNannies

“”Since teens report that they can get pot more easily than beer or cigarettes,””

“”Nobody who dislikes jail will be sharing with minors.”” (if it becomes legal, and ubiquitous, and grown everywhere)

Huh?


20 posted on 08/28/2012 2:24:47 PM PDT by ansel12 (Massachusetts Governors, where the GOP goes for it's "conservative" Presidential candidates.)
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